President Donald Trump has bashed the Democrats for a hugely controversial policy created by his own administration: separating undocumented immigrant children from their parents.

He urged Americans in a Saturday morning tweet to “put pressure” on the Democrats to “end the horrible law that separates children from there [sic] parents.”

Put pressure on the Democrats to end the horrible law that separates children from there parents once they cross the Border into the U.S. Catch and Release, Lottery and Chain must also go with it and we MUST continue building the WALL! DEMOCRATS ARE PROTECTING MS-13 THUGS.

Despite what Trump tweeted, there is no law requiring children to be separated from their parents. The separation policy was adopted by his own administration. It was underscored in a speech in early May by Attorney General Jeff Sessions (in the video above).

No law requires this — separating parents and children is your administration’s choice.

Hundreds of kids as young as 18 months are in danger of suffering lifelong trauma.

The policy has been hit with a firestorm of criticism, with some even comparing the increasing dehumanization of immigrants in America as similar to the ugly atmosphere in Germany before the Holocaust.

The Holocaust did not end with people being called subhuman, constantly compared to criminals, put into yellow markers with children torn from the the arms of screaming mothers..

Rep. Ted Lieu (D-Calif.) took first lady Melania Trump to task in light of her new “Be Best” mission for children. “Separating toddlers from parents is definitely not a ‘Be Best’ policy,” he tweeted. “Are you going to do anything about it?”

Dear @FLOTUS: Separating toddlers from parents is definitely not a #BeBest policy. Are you going to do anything about it?

No one can take your #BeBest children's agenda seriously when your husband's policy rips kids from their parents and loses track of the children. https://t.co/IQTSrvTVP4

Until recently, families that illegally crossed the Mexican border together generally faced civil deportation proceedings. But as of May, the Trump administration is sending all parents to jails run by the U.S. Marshals Service. Because migrant children cannot be held in jails, they are placed elsewhere by the HHS Office of Refugee Resettlement. Before the Trump administration, the office handled children who crossed the border alone.

White House chief of staff John Kelly, who called the harsh new policy a “technique” and a “tough deterrent,” explained earlier this month to NPR: “They’ll be sent to foster care — or whatever. But the big point is they elected to come illegally into the United States.”

CORRECTION: A previous version of this story identified Ted Lieu as a U.S. senator. He is a U.S. representative.